Issues with the top shaft oil pump in Siemens motors
Thread Content
Recently, when starting a motor in one of our units, the system shut down automatically due to low pressure in the jacking oil pump (at that time, the pressure of the jacking oil pump at the DE end was 2.9 MPa, while it was 2.5 MPa at the NDE end). We then adjusted the pressure of the jacking oil pumps for the motor (to 3.5 MPa at the DE end and 3.0 MPa at the NDE end). After restarting the motor, high vibration levels were detected, which led to another automatic shutdown. Currently, we have disconnected the coupling and are operating the motor in single-mode; each time the pressure difference before and after adjustment is changed by 0.5 MPa, the motor experiences high vibration and an alarm triggers automatic shutdown. We would like to ask the experts whether there are any regulations regarding the adjustment of the thrust oil pressure at the DE and NDE ends of this motor. Thank you!
The manufacturer must have written it before shipping; take a look at the user manual.
Should the top shaft oil pump stop automatically after the motor starts? This pump is mainly used to provide lubrication when the motor is not running; it is no longer needed once the motor starts
And how is this pressure regulated? Is there a flowchart? The outlet pressure of our motor cannot be adjusted; it’s also from Siemens